Marina crenulata
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Title
Marina crenulata
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Authors
Rupert C. Barneby
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Scientific Name
Marina crenulata (Hook. & Arn.) Barneby
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Description
28. Marina crenulata (Hooker & Amott) Barneby
(Plate XXI)
Tall erect, suffrutescent herbs from a tough woody root, with 1-several, at first herbaceous but at length lignescent, wandlike stems up to 6-20 dm long, glabrous throughout, the stems livid-castaneous and usually glaucous, finely striate but smooth and eglandular, the main axis appearing simple up to the small, few-branched, terminal panicle, the inflorescences mostly terminal to short-shoots or leafy spurs issuing from axils of drought-deciduous cauline leaves, the foliage bicolored, the leaflets green above, pallid and punctate beneath, lineolate both sides, the margins impressed- glandular-crenulate; leaf-spurs 0.4-0.8 mm long; stipules 0.5-3 mm long (variable according to var.); intrapetiolular gland subulate or spiculiform; post-petiolular glands subulate, acute, very prominent; main cauline leaves (seldom present on flowering material) 1.5-2.5 cm long, subsessile, with strongly veined rachis and 9-14 pairs of narrowly oblong, obtuse but gland-mucronate, flat leaflets 2-4 mm long, the rameal leaves usually crowded on lateral spurs 0.3-4 cm long, shorter than the primary cauline ones, mostly 0.5-2 cm long, with only 3-7 (9) pairs of leaflets mostly (0.5) 1-2 mm long; racemes mostly terminal to short-shoots, sessile or subsessile, (3) 6- 20-flowered, but a few (early in the season) terminating branchlets of a terminal panicle and these pedunculate and up to 30-flowered, the flowers loosely spreading or a trifle declined, the axis (0.2) 0.5-2.5 (3) cm long; bracts early deciduous from spurs decurrent on the axis, broadly lanceolate to ovate-acuminate, boat-shaped, brown and papery, sparsely glandular dorsally, pectinately ciliolate; pedicels 0.6-1 mm long, charged at apex with a pair of gland-grains; calyx (4) 4.5-6.2 mm long, glabrous, the brownish tube (1.2) 2.2-3.5 mm long, strongly pleated, the rather firm intervals charged with one row (or below the broad ventral teeth two rows) of 7-13 (17), rarely only 3 small yellowish glands, the plane herbaceous teeth dissimilar, the dorsal one broadly lance-ovate, 2.1-3 mm long, the ventral pair deltate-ovate, about twice broader and somewhat shorter than the dorsal one, the lateral pair intermediate, the bases of all teeth imbricate (dorsal exterior on both sides, laterals exterior to ventrals), the margins narrowly membranous-margined and minutely gland-serrulate or -crenulate, the orifice subsymmetrical; petals magenta-purple, the banner white centrally and distally, often gland-sprinkled, the keel-blades paler along their outer edge, the inner petals perched (1.2) 1.7-3.6 mm above hypanthium rim; banner 2.7-4.7 mm long, scarcely or not much exserted, the claw 1.3-3 mm long, the deltate-cordate or subquadrate blade 1.8-2.8 mm long, 2.6-3.4 mm wide, closed across top of claw to form a cornet; wings 3.7-5 mm long, the claw (often inversely subulate) 0.3-0.7 mm, the obovate blade 3.6-4.6 mm long, 2.7-3.2 mm wide; keel (5) 5.3-8.1 mm long, the claw 1.1-1.9 mm, the broadly oblong-obovate blade (4.4) 4.9-6.3 mm long, 3.2-4.9 mm wide; androecium 10-merous, 6.9-10.2 mm long, the longer filaments free for 1.7-2.3 mm, the connective gland-tipped, the bluish anthers 0.7-0.95 mm long; pod (glabrous) obovate or incipiently harp-shaped in profile, substipitate at base, ±2.5 mm long, the short style-base terminal but excentric, carinate dorsally above the pore and also ventrally, the valves membranous at very base, thence firm and charged with 2 (3) crescents of blister-glands.
In the field M. crenulata is recognized by its habit of growth, unlike that of related species. The mature plant consists of one or several tall and coarse, wandlike stems which branch distally into a disproportionately small, few-branched panicle of racemes. These, however, are flowers found only at the beginning of the dry season, when much of the primany cauline foliage still clothes the upper half of the usually purplish-glaucescent stem. The main crop of flowers does not appear before late January, in the form of densely, often subcapitately few-flowered racemes borne sessile on little leafy spurs axillary to the main cauline leaves which have dried up and fallen away. This type of inflorescence, appearing late in the dry season, is strikingly simulated by sympatric forms of Dalea versicolor, but is not otherwise matched in Marina. In the herbarium M. crenulata is sometimes confused with M. nutans, in which all the flowers, similar in form and coloring, are arranged in a panicle of loosely flowered racemes. The suffruticose and glabrous marina common in the range of M. crenulata is M. diffusa, but this is entirely different in its effuse, broad-headed inflorescence of distantly few-flowered racemes borne on filiform, pliant branchlets.
The range of typical M. crenulata along the Pacific slope from southern Sonora to western Jalisco is fairly well documented. There is one record for coastal Guerrero (rio Tecpan), apparently typical, and another from coastal Oaxaca, this remarkable for its enlarged, persistent stipules, relatively well-developed terminal panicle, few calyx-glands, and small flowers. The latter seems to differ sufficiently to deserve taxonomic recognition, but its status will obviously require revision as more material of M. crenulata from the coastal lowlands of Sierra Madre del Sur becomes available.